Explicitely state the outFile will not write file on disk

README.md

@@ -218,6 +218,26 @@ Default: `null`
 
 Specify the intended location of the output file. Strongly recommended when outputting source maps so that they can properly refer back to their intended files.
 
+**Attention** enabling this option will **not** write the file on disk for you, it's for internal reference purpose only (to generate the map for example).
+
+Example on how to write it on the disk
+```
+sass.render({
+    ...
+    outFile: yourPathTotheFile,
+  }, function(error, result) { // node-style callback from v3.0.0 onwards
+    if(!error){
+      // No errors during the compilation, write this result on the disk
+      fs.writeFile(yourPathTotheFile, result.css, function(err){
+        if(!err){
+          //f ile written on disk
+        }
+      });
+    }
+  });
+});
+```
+
 ### outputStyle
 Type: `String`
 Default: `nested`